The present disclosure relates to an apparatus for measuring the propagation velocity of a sound wave, and more particularly, to a system for measuring the propagation velocity of a sound wave that may easily and accurately measure the propagation velocity of a sound wave passing through many sample materials such as marine sediment, and a method of measuring the propagation velocity of a sound wave by using the system.
Also, the present invention relates to a system for measuring the propagation velocity of a sound wave that may easily and accurately measure the propagation velocity of a sound wave passing through many materials such as a sample of marine sediment by using a fixing unit for preventing a measurement unit from vibrating and a distance measurement unit capable of accurately measuring the distance between ultrasonic transmission and reception units, and a method of measuring the propagation velocity of a sound wave by using the system.
In addition, the present invention relates to a system for measuring the propagation velocity of a sound wave that may easily and accurately measure the propagation velocity of a sound wave in the horizontal and vertical directions of the sample by using a typical sampling case for collecting a sample of marine sediment as it is, and a method of measuring the propagation velocity of a sound wave by using the system.
In general, collecting and analyzing marine sediment, examining the physical property of the marine sediment, and utilizing such a matter as fundamental data for studying geosciences and mineral resources are very important in studying the geosciences and mineral resources.
However, there are many difficulties in going down to the sea bottom of corresponding seas and analyzing sediment in order to examine the physical property of such marine sediment.
Thus, in order to solve such a difficulty, a method is being mainly used so far in which a sample of marine sediment is collected and carried to the laboratory, and measurement is then performed on the sample of marine sediment to analyze the property of sediment on a corresponding region.
In this example, when a sample is collected from a sedimentary layer located at the sea bottom, carrying a collected sample to the laboratory while maintaining its original state if possible is very important in addition to the collection of the sample.
Also, as an analysis method on the sample of marine sediment collected by using the method as described above, a method of acoustically measuring and analyzing the physical property of marine sediment by using acoustic equipment using a sound wave is being mainly used recently as a result of active research and development of such measurement equipment.
More particularly, in order to measure the thickness of the sedimentary layer located at the sea bottom by using the sound wave, work finding the propagation velocity of the sound wave that is different from one layer to another should be first performed.
That is, the propagation velocity of the sound wave through the marine sediment is needed for the analysis of an association with diagenesis or another physical property but the propagation velocity itself is recognized as important, and in this example, an appropriate velocity structure may be calculated through data analysis on an seismic wave but typical measurement apparatus and methods have had a big difference from real measurements in many cases.
In particular, accurately measuring the propagation velocity of the sound wave on the marine sediment is needed in order to calculate acoustic impedance directly connected to an accurate reflection surface location and a reflection coefficient, and to this end, sampling on a selective core sample should be first performed to be capable of measuring the propagation velocity of the sound wave depending on each depth on a marine sediment core sample obtained from the marine sediment, and then accurate measurement should be performed through the sample obtained in such a way.
In this example, the selective sampling on the core sample as described above may be easily performed by Korean Patent Application No. 10-2012-0100371, filed on Sep. 11, 2012 by the inventors and applicants of the present invention, entitled “SAMPLING CASE FOR MEASURING PROPAGATION VELOCITY OF SOUND WAVE OF MARINE SEDIMENT AND SAMPLING DEVICE INCLUDING THE SAMPLING CASE”, for example.
More particularly, Korean Patent Application No. 10-2012-0100371, entitled “SAMPLING CASE FOR MEASURING PROPAGATION VELOCITY OF SOUND WAVE OF MARINE SEDIMENT AND SAMPLING DEVICE INCLUDING THE SAMPLING CASE” as mentioned above relates to a sampling device that includes a sampling case having a hole on each surface to be capable of collecting some samples from core samples obtained by boring a hole though the marine sediment and measuring the propagation velocity of the sound wave in the horizontal and vertical directions from the samples collected, and a plurality of cases capable of being positioned to collect a plurality of samples from a desired location on a core sample and perform depth-dependent sampling.
Thus, by using Korean Patent Application No. 10-2012-0100371, entitled “SAMPLING CASE FOR MEASURING PROPAGATION VELOCITY OF SOUND WAVE OF MARINE SEDIMENT AND SAMPLING DEVICE INCLUDING THE SAMPLING CASE” as mentioned above, a sample is easily collected from the sedimentary layer at the sea bottom and a collected sample is placed on a measurement apparatus so that the sound wave is measured in the vertical and horizontal direction.
Also, an example of a typical measurement apparatus for measuring the sound wave of a sample includes Korean Patent No. 10-0445371 published on Aug. 12, 2004, entitled “SEISMIC WAVE VELOCITY MEASUREMENT SYSTEM FOR UNCONSOLIDATED SEDIMENT CORES”.
More particularly, Korean Patent No. 10-0445371, entitled “SEISMIC WAVE VELOCITY MEASUREMENT SYSTEM FOR UNCONSOLIDATED SEDIMENT CORES” as mentioned above relates to an apparatus for measuring the propagation velocity of a seismic wave of an unconsolidated sedimentary layer by using the P wave of seismic waves, and includes a sound generation unit including an instantaneous sound generator, a high-voltage generator and a pre-amplifier, a transmission and reception unit including oscilloscope sensing a signal to represent the signal on cathode ray tube (CRT), a sample holder for holding the shape of the sample and a transceiver including piezoelectrics, and a display unit connected to personal computer (PC).
However, the measuring system of Korean Patent No. 10-0445371 as mentioned above has limitations in that since a measurement unit measuring by holding the sample to transmit and receive an ultrasonic wave is configured to play only a role in simply fixing the sample holder between transmission and reception units, a separate fixing unit for fixing the measurement unit itself is not installed and a separate distance measurement unit for checking an accurate distance between transmission and reception units is not installed either.
That is, when the sound wave is measured, the measurement apparatus should be rigidly fixed so that a measurement is not affected by the vibration of the measurement apparatus, and when a distance between the transmission and reception units varies depending on the size of a sample held between the transmission and reception units, such a change in distance also affects a measurement result. Thus, exactly knowing the distance between the transmission and reception units to reflect the distance to a measurement result is needed but typical measurement apparatuses generally focus on holding the sample to measure an ultrasonic wave and the measurement system allowing the measurement apparatus itself to be fixed and allowing the distance between the transmission and reception units to be measured has not been presented.
Thus, in order to more accurately measure the sound wave on a sample as described above, a measurement system that includes a fixing unit for preventing a sound wave measurement apparatus from vibrating and a distance measurement unit capable of accurately measuring a distance between ultrasonic transmission and reception units should be provided but a measurement system or measurement method that satisfies such a need has not been presented.
In addition, in measuring the propagation velocity of a sound wave, when both the fixing unit for preventing the measurement unit from vibrating and the distance measurement unit capable of accurately measuring the distance between the ultrasonic transmission and reception units as described above are installed and it is possible to install a typical sampling case for collecting a sample of marine sediment on the measurement unit as it is to measure the propagation velocity of a sound wave in the horizontal and vertical directions of the sample, it is contemplated that measurement work is very easy and accurate measurement is possible. However, a measurement system or measurement method that satisfies all of such needs has not been presented.